High voltage visible oil switch



Oct. 10, 1967 R. B. WESTON ETAL 3,346,710

HIGH VOLTAGE VISIBLE OIL SWITCH Filed July 12, 1965 (III I I ATTORNEYUnited States Patent 3,346,710 HIGH VOLTAGE VISmLE OIL SWITCH Ralph B.Weston, Culver City, and Albert E. Colato,

Tujunga, Calif., assignors to Plastics, Inc, a corporation of MinnesotaFiled July 12, 1965, Ser. No. 471,269 Claims. (Cl. 200-150) ABSTRACT OFTHE DISCLOSURE A high voltage visible oil switch device comprising asealed housing having peripheral transparent side walls, a pair ofstationary contact blades, a body of oil within the housing to a pointabove the level of said contact blades, a circuit breaker with bladesupports, a handle connecting the upper ends of said blade supports, anda lever extending beneath said handle between said blade supports bymeans of which said handle may be raised.

This invention relates to an improvement in high voltage visible oilswitch and deals particularly with a switch which may be operated with aminimum of arcing.

Street lighting systems are usually operated by high voltage, lowamperage circuits. Usually a single circuit may be provided for aconsiderable number of street lights so that the entire series of lightsmay be turned on and off simultaneously. Circuits of this type ofteninclude safety switches which are operated only in an emergency or whenit is the desire to isolate a certain portion of the circuit. As aresult, such switches are seldom used and tend to deteriorate throughlack of use. Furthermore, switches of this type are seldom inspectedbecause of a difficulty involved in making the inspection. Failure ofthe switch to function properly may be extremely dangerous, particularlywhere the switch is designed for use in a shorting circuit or agrounding circuit.

An object of the present invention resides in the provision of a switchwhich is enclosed in a transparent plastic housing so that all of theoperating elements of the switch are visible. As a result, the switchmay be inspected without danger to the inspector and without exposingthe operating elements of the switch by opening the housing.

A feature of the present invention lies in the provision of a switch inwhich the contacts are emersed in transformer oil, the oil acting toquench any arcing between the blades as the switch is operated. The oilemployed is sufficiently transparent so that the contact blades may beviewed through the transparent housing encircling the switch.

A further feature of the present invention resides in the provision of aswitch of the type described which is impervious to the vagaries ofweather conditions and corrosion. As the switch contacts are emersed inthe transformer oil, a minimum of arcing take place when the switch isoperated. As a result, the switch may outlast most switches used forsimilar purposes.

A further feature of the present invention resides in the provision of aswitch of the type described including a means of automatically lockingthe switch in closed position. When the switch is closed, locking meansis provided to prevent the switch contacts from being spread apart bythe switch opening wedge.

A further feature of the present invention resides in the provision of aswitch of the type described in which a pair of contacts resilientlyurged into contact to close the circuit. The contacts are provided withdiverging end portions. An insulating wedge is supported forreciprocating movement toward and away from the contacts, and in oneextreme position engages between the cont-act ledge to hold them inspaced relation. The wedge is properly designed to hold the wedgefrictionally engaged between the contacts so that it cannot accidentallymove from between the contacts to accidentally close the circuit.

An added feature of the present invention resides in the provision of aswitch of the type described which can be produced at a relatively lowcost of production.

These and other objects and novel features of the present invention willbe more-clearly and fully set forth in the following specification andclaims:

In the drawings forming a part of the specification;

FIGURE 1 is an elevational view of the switch showing the constructionthereof.

FIGURE 2 is a side elevational view of the switch shown in FIGURE 1, apart of the switch being broken away on the section line 22 of FIGURE 1.

FIGURE 3 is a vertical sectional view through the switch, showing theswitch in closed position, the position of the section being indicatedby the line 2-2 of FIGURE 1.

FIGURE 4 is a top plan view of the switch.

The switch, which is indicated in general by the letter A, is mounted ona support usually having a vertical surface 10 and indicated in generalby the letter B. The body of the switch supported by a generallyrectangular mounting plate 11, the corners of which are suitablyapertured to accommodate mounting screws or mounting bolts 12. Adjoiningthe top of the plate 11 and on opposite sides of the center line of, apair of generally parallel cars 13 project. An operating lever 14 whichwill be later described in detail is pivotally connected between thecars by the pivot 15. Below the cars 13, the center portion is bulgedforwardly as indicated at 16, the forward surface of the forwardlyextending portion 16 having a concave inner surface 17 to form a cradleand to fit the contour of the cylindrical wall 19 of the switch body.

The top of the cylindrical wall 19 is closed by means of a closure plate20 which is sealed against the upper planar surface of the cylindricalwall 19. A rearward projection 21 is provided extending radially fromthe top plate 20 and anchoring screws 22 extend through this projectingportion 21 of the top cover plate 20 and into the upper end of theforwardly bulged portion 16 of the mounting plate 11 as may perhaps bebest seen in FIG- URE 3 Of the drawings.

The lower end of the cylindrical sleeve 19 is closed by a bottom closureplate 23 which is of somewhat larger diameter than the sleeve 19 and isconcentric therewith. The lower edge of the sleeve 19 is sealed to theupper surface of the bottom closure plate 23. The bottom closure plate23 also includes a rearwardly extending projection 24 which extendsbeneath the forwardly bulged portion 16 of the mounting plate 11. Screwsor similar means 25 eX- tend upwardly through the projection 24 and intothe lower end of the bulged portion 16 of the plate 10 as is alsoperhaps best illustrated in FIGURE 3 of the drawings.

The switch A also includes a lower housing which is indicated in generalby the numeral 27. The lower housing 27 includes a cylindrical wall 29,the outside diameter of which is substantially equal to the outsidediameter of the bottom closure plate 23. The bottom also includes abottom wall 30 forming a bottom closure for this bottom housing. Thelower housing 27 is divided into two separate compartments by adiametrically extending partition Wall 31. The lower housing 27 isremovable from the rest of the switch body and is normally securedthereto by bolts or screws 32 which extend upwardly through thepartition 31 and into the bottom closure plate 23 to hold the partsassembled. The bottom wall 30 is provided with a pair of spacedapertures 33, one of which communicates with each of the twocompartments. As is indicated in FIGURES 1 and 3 of the drawings, thepurpose of these apertures is to accommodate conducting wires.

Two pairs of contacts 34 are mounted within the cylindrical wall 19.Each pair of contacts is formed as is best illustrated in FIGURES 2 and3 of the drawings. Each contact includes a horizontally extending lowerend portion 36, an upwardly extending portion 37 extending upwardly froman edge thereof, an inwardly inclined portion 39, and an outwardlyinclined portion 40 at the upper edge thereof. There is a roundedportion 41 between the inclined portions 39 and 40 which swing intocontact with the opposed contact member as is indicated in FIGURE 3 ofthe drawings when the contacts of each pair are not held apart. To addstrength to each contact, an outer reinforcing blade 42 forms a part ofeach contact member 34. Each reinforcing blade includes a horizontalportion 43 which overlies the horizontal portion 36 of the previouslydescribed blade, an upwardly extending portion 44 connected to an edgethereof and extending upwardly generally parallel to the blade portions37, and an inwardly inclined arm 45 at the upper end of the portion 44which engages against the outwardly inclined portion 40 of the innerblade to add strength thereto and to urge the inner contact bladeintocontacting relation.

The contacts of each pair are mounted upon rectangular insulation blocks46 and 47. Conductive screws 49 and 50 extend through the horizontalportions 36, 42 of the contacts 34 and the similar portions of thecontacts 35 and also extend through the bottom closure plate 23. Onescrew 49 and 50 of each pair extends into the chamber on one side of thecenter partition 32, and the other bolt of each pair extends into theother chamber. Angle brackets 51 and 52 are secured to the bolts 49 and50 by suitable nuts 53 and 54. The vertical portions of the anglebrackets 51 and 52 are provided with anchoring bolts 55 and 56 to whichinsulated conductors such as 57 and 59 may be detachably secured.

As will be obvious, the wiring of the switch may be varied to suit thetype of circuit employed.

An elongated wedge-shaped circuit breaker 60* is provided to break thecircuit between the contacts of each pair, and this member may alsoserve to simutaneously make contact between one contact member of eachpair and a corresponding contact member of the other pair. The member 60is relatively narrow at its lower end 61 and relatively wider at itsuper end 62. The member 60 also includes opposed notches 63 in itsopposite sides, the walls of the notches 63 generally to the shape ofthe upper portions of the contact blades when the wedge is between theblades, as indicated in FIGURE 2 of the drawings. Normally, the member60 is made of insulation material, but opposite sides of the wedge maybear strips 64 of conductive material which may serve to electricallyconnect one contact of each pair with a corresponding contact of theother pair when the wedge is between the contact blades as shown inFIGURE 2.

The contact flexing wedge 66 is supported by a pair of parallel rods 66which extend vertically from the upper surface 62 of the member 60 andextend through the upper closure plate 20. The upper ends of theparallel rods 66 extend into a transversely extending handle 67 whichserves as a connection between the rods. The handle 67 extends above theoperating lever 14 which is pivoted to the mounting plate ears 13. Thus,upward movement of the handle lever 14 will raise the wedge 60 from theposition shown in FIGURE 2 of the drawings to the position shown inFIGURE 3. The handle lever 14 is vertically slotted as indicated at 69to provide a forward bifurcated end. If desired, this slot 69 may extendonly through the center portion of the handle, leaving the forward endthereof solid. A locking arm 70 is provided in the slot 69 and ispivotally connected to the handle by a transverse pivot 71. The pivot 71is preferably located generally above the center of the top closureplate 20. The center of the top closure plate 20 is provided with anindentation 72 into which the free end of the lever 70 may extend.Accordingly, when the handle lever 14 is swung upwardly, the free end ofthe lever 70 slides toward the center of the top closure plate 20 untilit is engaged in the indentation 72. When in this position, the lever 14is locked in the position shown in FIGURE 3, and the handle 67 may notbe lowered until the locking lever is disengaged.

Sealing collars 73 preferably encircle the rod 66 above the top closureplate 20 to prevent the entrance of moisture into the sleeve 19. Aremovable filling plug 74 is provided in the top closure plate 20 (seeFIGURE 4) by means of which the oil in the switch housing may bereplenished.

The oil level is usually maintained well above the surface of thecontacts to prevent corrosion and to reduce arcing. The wedge 60 isnormally raised from a position between the contacts to the positionshown in FIGURE 3 by means of the lever 14. When desired, the wedge 60may be returned to its lowered position by a downward force on thehandle 67.

In accordance with the patent statutes, the principles of constructionand operation of this improvement in high voltage visible oi-l switchhave been described, and while an endeavor has been made to set forththe best embodiment thereof, it should be understood that changes may bemade within the scope of the following claims without departing from thespirit of the invention.

We claim:

1. A switch comprising:

a sealed switch housing including a bottom closure plate, a top closure,and peripheral transparent side walls connecting said top and bottomclosures and sealed relative thereto,

insulation block means overlying said bottom closure,

a pair of spring contact blades having angularly turned lower endsmounted on said insulation blocks and normally biased into contact,

clamping bolts extending through the angularly turned lower ends of saidblades, through said insulation block means and through said bottomclosure plate,

means on said clamping bolts to clamp them in position and providing aliquid tight seal with said bottom closure plate,

a body of oil within said housing the liquid level of which is abovesaid contact blades,

a circuit breaker,

means on said top closure supporting said circuit breaker for movementfrom a position between said blades to a position above said blades,

a terminal housing extending downwardly from said bottom closure intowhich said clamping bolts extend, and

a central partition of insulating material within said terminal housingbetween the lower ends of said clamping bolts providing a pair ofside-by-side terminal housing chambers.

2. The structure of claim 1 and in which said supporting means isslidably supported by said top closure, and in which said top closureincludes bearing means snugly accommodating said supporting means inboth positions thereof.

3. A switch comprising:

a sealed switch housing including a top closure, a bottom closure, andperipheral transparent walls connecting said closure,

a pair of resilient contact blades including horizontal lower endportions, upwardly and inwardly inclined intermediate portions, andupwardly and outwardly inclined upper end portions arranged in opposedrelation and normally in contact at the juncture between theintermediate portions and the upper end portions,

electrically conductive blade securing means extending through saidhorizontal blade portions and said bottom closure,

a circuit breaker blade,

a pair of parallel breaker blade supports secured to said circuitbreaker blade and extending through, and slideably supported by said topclosure,

said blade supports supporting said breaker blade for movement from aposition between said blades to a position above said blades, and

a handle connecting the upper ends of said blade supports.

4. The structure of claim 3 and including a lever pivotally supported ona horizontal pivot above said top closure and extending beneath saidhandle between said blade supports by means of which said handle may beraised.

5. The structure of claim 4 and including a locking arm pivotallyconnected to said lever on a horizontal axis and engageable with saidtop closure when said lever is swung upwardly to lock said lever fromdownward movement.

6. A switch including:

a switch housing including a top closure and a bottom closure, and aperipheral wall connecting said closures,

two pairs of contact blades mounted on said bottom closure and extendingupwardly therefrom,

the blades of each pair being in opposed relation and normally biasedinto contacting engagement, and the blades of one pair being alignedwith the blades of the other pair,

the blades of each pair having upwardly and outwardly diverging upperends,

a contact breaker bar,

a pair of parallel supports extending through said top closure andsupporting said breaker bar for movement from a position between theblades of each pair to a position above said blades,

said housing having a relatively electrically non-conductive fluidtherein to a level above said blades, and

a handle connecting the upper ends of said parallel supports by means ofwhich said breaker bar may be actuated between said positions.

7. The structure of claim 6 and in which said breaker bar istransversely notched on opposite sides thereof, the notchesaccommodating the portions of the contact blades which contact oneanother when the breaker bar is in position above the blades.

8. The structure of claim 6 eral Walls are transparent.

9. The structure of claim 6 and including a terminal chamber beneathsaid switch chamber and supported thereby, said terminal chamber beingsealed relative to the interior of the said switch housing, and

terminals in said terminal chamber each connected to a correspondingsaid blade.

10. The structure of claim 9 and including an insulation wall in saidterminal chamber dividing one terminal of each pair from the otherterminal thereof.

References Cited and in which said periph- UNITED STATES PATENTS1,011,639 12/1911 Murray et al. 20015 X 1,562,183 11/1925 Norton200153.14 1,629,158 5/1927 Griswold 200-163 1,951,297 3/ 1934 Nor-mann200l51 2,598,162 5/1952 Guiot 20019 ROBERT K. SCHAEFER, PrimaryExaminer. H. BURKS, Assistant Examiner.

3. A SWITCH COMPRISING: A SEALED SWITCH HOUSING INCLUDING A TOP CLOSURE,A BOTTOM CLOSURE, AND PERIPHERAL TRANSPARENT WALLS CONNECTING SAIDCLOSURE, A PAIR OF RESILIENT CONTACT BLADES INCLUDING HORIZONTAL LOWEREND PORTIONS, UPWARDLY AND INWARDLY INCLINED INTERMEDIATE PORTIONS, ANDUPWARDLY AND OUTWARDLY INCLINED UPPER END PORTIONS ARRANGED IN OPPOSEDRELATION AND NORMALLY IN CONTACT AT THE JUNCTURE BETWEEN THEINTERMEDIATE PORTIONS AND THE UPPER END PORTIONS, ELECTRICALLYCONDUCTIVE BLADE SECURING MEANS EXTENDING THROUGH SAID HORIZONTAL BLADEPORTIONS AND SAID BOTTOM CLOSURE, A CIRCUIT BREAKER BLADE, A PAIR OFPARALLEL BREAKER BLADE SUPPORTS SECURED TO SAID CIRCUIT BREAKER BLADEAND EXTENDING THROUGH, AND SLIDEABLY SUPPORTED BY SAID TOP CLOSURE, SAIDBLADE SUPPORTS SUPPORTING SAID BREAKER BLADE FOR MOVEMENT FROM APOSITION BETWEEN SAID BLADES TO A POSITION ABOVE SAID BLADES, AND AHANDLE CONNECTING THE UPPER ENDS OF SAID BLADE SUPPORTS.